Making a soil block using the PotterFactory Tool is quite frankly, well ... incredible !
We try to be humble but sometimes it's not easy, but making a soil block sure is.

Grab your favorite pre-mix, or whip-up a simple one.  Spread the mix out like cookie dough and cut cookies with the blocker form, or scoop up your mix from a bag.  Nothing could be simpler. Our unique compression system allows you to apply over Four Times the amount of force.  Using the proper mix you will produce denser and more durable soil blocks.  

We usually start with Hyponex potting soil, which without amendments is something most gardeners dislike, but with the proper additions becomes very likeable.  Hyponex is inexpensive, and contains about 50% sedge peat, a decomposed plant fiber which is used under golf course greens for water retention; it is also PH neutral. Seeds like very moist loose material in which to germinate, and more dense and nutritious, but water retentive soil in which to put down roots. In a perfect world a soil block would have a structure to do both. Welcome to a nearly-perfect world.  

Take two plastic containers. For mix A, use some basic potting soil such as Hyponex and get a bag of sphagnum peat: Use one part of each and mix together dry, then add water so it is saturated but no water standing, spread it about 3/4" thick - this is a germination mix.  For mix B use 4 parts Hyponex, 2 parts sphagnum peat, 1 part sand, 1 part leaf compost or some type of compost, and to this we like to add one part sphagnum moss (cut up with scissors into 1" long fibers, more or less) and 1/2 part fireplace ash. Sphagnum moss is the dried long fiber product that is used in potting things like orchids - it absorbs and holds water and is perfect in soil blocks. The ash helps buffer the acid in the sphagnum moss and provides potash. Mix this up dry then add water until well saturated but no standing water, and spread about 2" thick.

Now stick your potterfactory tube into the mix A, turn the tube over and stick the opposite open end into mix B just like you are cutting cookies, stick in the compressor and press hard. Now spin/twist the compressor -- sometimes the mix is sticky, and with light pressure now on the compressor, slide the tube up and off. Before you slide the tube off you may want to grab an unsharpened pencil and make a seed hole in the top of the block.  Dip the tool in a bucket of water if it gets dirty.

We like to use a taller soil block and make them 2 3/4" high, this provides a deep area for the development of a large root mass. Make a felt-tip mark or place a piece of black tape 2 3/4" down from the open end of the compressor - this will guide you in making each block exactly the same height. Because you keep them moistened and they hold plenty of water, tipping over is really not a problem. These soil blocks should be bottom watered. They will hold their shape, and will drop right into a paper pot if ever desired. They have the top portion designed for ideal germination, and the bottom portion designed for water, nutrients, and establishing good roots. You will want to design your own perfect mix but this is a good point to start.